Improvements to Disordered Rocksalt Li-Excess Cathode ... · 7/4/2018 · EV and E-Bus Markets are...

Accelerating Breakthrough Discoverieswww.wildcatdiscovery.com

Improvements to Disordered RocksaltLi-Excess Cathode Materials

July 4, 2018Wildcat Confidential 1

Kyler Carroll1, Bin Li1, Dee Strand1, Robson Monteiro2, Rogerio Ribas2, Jon Jacobs1

1Wildcat Discovery Technologies (San Diego, CA)2Companhia Brasileira de Metalurgia e Mineração (CBMM) (Araxá Minas Gerais, Brazil)

Presentation Outline

▪ The LIB Cathode Market

o The Herd

o The Opportunity

▪ Disordered Rocksalt

o How it’s Different

o Performance Challenges

o Development Progress

▪ Summary



The transportation market is driving enormous LIB demand

EV and E-Bus Markets are Growing Rapidly

-

50,000

100,000

150,000

200,000

250,000

300,000

350,000

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

LIB Use by Application (MWh)

Electronics

Auto

Bus

Other

Source: Avicenne Energy

Auto + Bus = Electronics

Auto + Bus = 3X Electronics

Auto + Bus = 8X Electronics

Lithium-Ion Cathode Demand – 2010 vs. 2017


-

20,000

40,000

60,000

80,000

100,000

120,000

LCO NMC NCA LMO LFP

LIB Cathode Demand by Chemistry (Tonnes)

2010

2017

NMC and LFP use have grown dramatically since 2010


32% of the cathode marketIn 2017


NMC is the heavy favorite for automotive applications

2017 Cathode Demand (Tonnes) by Market

Auto Consumer Electronics



-

100,000

200,000

300,000

400,000

500,000

600,000

700,000

LCO NMC NCA LMO LFP

LIB Cathode Demand by Chemistry (Tonnes)

2010

2017

2025

NMC is forecast to take over 70% of the global market by 2025

70% of the cathode market!

Lithium-Ion Cathode Demand – 2010 vs. 2025


Cobalt Concerns


What can be done to reduce our reliance on cobalt?

Source: https://www.cobaltinstitute.org/statistics.html

2018 price

The Move to Higher Nickel NMC’s


-

50,000

100,000

150,000

200,000

250,000

300,000

350,000

NMC 111 NMC 532 NMC 622 NMC 811

NMC Demand by Ni Content (Tonnes)

2017

2020

2025

More nickel, less cobalt

▪ Strong move toward higher nickel content NMC’s

▪ Reduction of Co content from 33% to less than 10%

▪ And even higher nickel versions are being considered (>90%)

NMC 811 is one of the world’s most popular near-term R&D targets


Energy Improvements are Possible, but Modest


Increase energy

▪ Cell energies have increased 3% per year, but are near cathode theoretical limits

▪ Increased voltage leads to higher energies…

▪ …but introduces electrolyte stability and gas generation challenges

Are there alternatives to NMC…with higher energy and no Cobalt?


Cathode Material Energy


437531

610700 714 716 742

950

2450

0

500

1000

1500

2000

2500

3000

LMO LFP NMC111

LMNO LCO NCA NMC811

Li-richNMC

Li-S

Wh

/kg

Gravimetric Energy Density vs. Chemistry Can we ever get here?

Commercial

Improvement needed

Large challenges

A gap exists between today’s LIB energies and post-LIB technologies

▪ Solid-state▪ Li-air▪ Hydrogen▪ ???

437531

610700 714 716 742

950

1200

1800

2450

0

500

1000

1500

2000

2500

3000

LMO LFP NMC111

LMNO LCO NCA NMC811

Li-richNMC

DR CuF2 Li-S

Wh

/kg

Gravimetric Energy Density vs. Chemistry

Cathode Material Energy


Commercial

Improvement needed

Large challenges

Advanced cathode opportunities

▪ Disordered rocksalt

▪ Conversion electrodes

Disordered rocksalt is a Co-free alternative to NMC with ~40-60% more energy

Headroom exists

437531

610700 714 716 742

950

1200

1800

2450

0

500

1000

1500

2000

2500

3000

LMO LFP NMC111

LMNO LCO NCA NMC811

Li-richNMC

DR CuF2 Li-S

Wh

/kg

Gravimetric Energy Density vs. Chemistry

Cathode Material Cost per kWh


DR offers a tremendous $/kWh value proposition

LMO LFP NMC LCO DR

$ / kg $19 $19 $28 $46 $23

$ / kWh $44 $41 $43 $80 $22

▪ Ni $18/kg▪ Co $60/kg▪ Mn $4/kg▪ Nb $41/kg▪ Li $33/kg

Source: LME

Ordered vs. Disordered Structures


Today’s cathodes are mostly ordered structures:▪ Li sites and pathways separated

from TM sublattice▪ Provides stability (good cycle life)▪ TM layers provide electron storage

capacity

Chen, Nanoscale Horiz., 1 (2016)

In a disordered rock salt:▪ Both Li and TM occupy a cubic close-packed

lattice of octahedral sites▪ Li diffusion occurs by hopping from one

octahedral site to another via an intermediate tetrahedral site (o-t-o diffusion)

▪ Very small changes in lattice parameters during cycling

Ceder, Science, 343 (2014)

Disordered structures appear to have performance advantages

Are Fast Kinetics Possible?


Tetahedron heights of disordered materials

Multiple possible pathways for Li transport

0-TM pathway is energetically favored

Li content needs to be high for 0-TM percolation

Ceder, Science, 343 (2014)

Percolation network provides means of fast lithium transport

Rich Compositional Space


Disordered rocksalts offer a rich compositional space to explore

Ceder, IMLB (2018)

NCM622 = 185 mAh/g

Nb-based Materials


Many cation ordered/disordered rocksalt phases on tie-line between MeO and LiO, including Li3Nb5+O4

However, Li3Nb5+O4 has poor capacity due to poor electronic conductivity, with no electrons in a conduction band (4d0 configuration for Nb5+)

Yabuuchi, PNAS, 112, 25 (2015)

Nb phases provide a particularly promising area for exploration

Disordered Material Capacity


TM substitution for some of the Nb5+ and Li+

induces electronic conductivity in Li3NbO4 –yielding capacities beyond limit of redox for TM’s

Electrochemical performance of Li1.3Nb0.3Mn0.4O2 (1.5 – 4.8V, 10 mA/g, 60oC)[0.43Li3NbO4-0.57LiMnO2]

Yabuuchi, PNAS, 112, 25 (2015)

Observed capacity is higher than theoretical based on TM redox

Disordered Rocksalt Challenges


1. Poor rate performance/conductivity

▪ Most literature results are at C/40

and at elevated temperature

2. Low discharge voltage

▪ Capacity above 3.0V is less than

250 mAh/g

3. Poor cycle life

▪ Mainly reported in half cells

Disordered materials have high energy, but other metrics need improvement

C/40

Ceder, Electrochem. Comm., 60 (2015)

Ph

ase

1P

has

e 2

High Throughput Material Development


Composition

• Li content

• Single dopants

• Multi dopants

• Dopant ratios

• Fluorination

Conductive Coatings

• Carbon

• Phosphates

• Fluorides

• Oxides

Synthesis Conditions

• Milling energy

• Time

• Particle size

Success depends upon finding the right combination of materials and processes

1000’s of materials…

100’s of processes…

Commerciallyready DR!

Conductivity Improvement via Composition


▪ Conductivity

sensitive to both Li

content and cation

mixing

▪ For given TM’s, Li

content can be

studied to optimize

conductivityCedar, Science, 343, 2014

Li+ percolation can be optimized by changing composition

Better…

Diminishing returns

Conductivity Improvement via Composition


Li content can be optimized, but other improvements are needed

Effect of Dopants on Performance


▪ Some TM’s can stabilize

the oxygen dimer

o d-band of TM

overlapping p-band

of oxygen

o Prevents O2 release

from material

Complex DOE’s required to optimize both lithium and dopant compositions

C/10 Capacity 1C Capacity

Base Formulation: Lix Nb0.10 My Mnz O2

Multipledopants

Dopantratios

Singledopants

Carbon Coating Can Improve Rate Performance


Performance is very sensitive to both base composition and carbon coating

C/10 Capacity 1C Capacity

Development Progress


Validation

Composition/Dopants Coatings

Combinations

Number of Cells

Complex DOE’s enable systematic improvements

~600 cells evaluated in only 4 months

Each point represents a unique material

Development Progress


▪ Wildcat improved

performance via:

o Elemental ratios

o Doping

o Carbon coating

▪ Specific energy of best

materials at 30oC outperform literature-

reported materials at 55oC

▪ Phase 2 development will

focus on improved cycle life

and voltage plateau

Wildcat’s disordered rocksalt has energy density of ~975 Wh/kg at room temperature

Summary

▪ Auto LIB market is driving tremendous growth in NMC demand

▪ Cobalt’s pricing and labor concerns - and the desire for more energy - are

driving a strong move to higher nickel NMC’s

▪ Disordered rocksalt offers a compelling alternative to NMC, with higher

energy, lower $/kWh and no reliance on cobalt

▪ Disordered materials inherently offer more energy than layered materials, yet

performance challenges exist: rate, cycle life, voltage plateau

▪ A vast DR compositional region remains unexplored with many opportunities

to further improve performance

▪ High throughput is an excellent means of rapidly evaluating hundreds of new

compositions

▪ DR is young, there are large improvements ahead!


Wildcat’s Business Model


Wildcat Website:www.wildcatdiscovery.com

High Throughput Video:https://youtu.be/Eu1nvrCzJWQ

Acknowledgements


▪ Rogerio Ribas▪ Robson Monteiro▪ Andre de Albuquerque Vicente▪ Frederico Carneiro

▪ Kyler Carroll▪ Bin Li▪ Dee Strand▪ Julie Goetz▪ Jacki Liyama▪ Alex Freigang

Thank you for your attention!

Contact Information

Mark Gresser

President & CEO

[email protected]

(858) 550-1980 x130

Dr. Dee Strand

Chief Scientific Officer

[email protected]

(858) 550-1980 x106

Jon Jacobs

Vice President, Business Development

[email protected]

(858) 550-1980 x114

6255 Ferris Square, Suite ASan Diego, CA 92121

www.wildcatdiscovery.com

7/3/2018Wildcat Confidential 29

Improvements to Disordered Rocksalt Li-Excess Cathode ... · 7/4/2018 · EV and E-Bus Markets are...

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